What is the ruling on giving charity and performing Hajj on behalf of a father about whom it was said that he used to slaughter for other than Allah, taking into consideration that scholars or guides were not available to him?

If the deceased's father was known for righteousness, it is not permissible to believe anyone who reports otherwise about him except with clear evidence. It is recommended to supplicate for him and give charity on his behalf. However, if it is established by just testimony that he died upon polytheism, such as being seen sacrificing to other than Allah or invoking others, then it is obligatory to refrain from supplicating and seeking forgiveness for him. His matter is with Allah, for the Prophet, peace and blessings be upon him, said: "I asked my Lord for permission to seek forgiveness for my mother, but He did not permit me. And I asked Him for permission to visit her grave, and He permitted me." As for one who died and the message did not reach him, his matter is with Allah, and he will be tested on the Day of Judgment.